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New approach to determine soil parameters free from regional variations in soil behaviour and technical quality
9A the shear zone of one slide and soils on the bedding plane. The direct shear test is shown to be a practical test method for evaluation of shear strength parameters for landslide analysis.
correlation between normalised undrained strength and Ip reported by other workers is not seen. The effect of strain rate on undrained strength is independent of Ip.
931062 New approach to determine soil parameters free from regional variations in soil behaviour and technical quality Hanzawa, H Soils Found V32, N1, March 1992, P71-84
931066 Estimation of shear characteristics degradation and stressstrain relationship of saturated clays after cyclic loading Matsui, T; Bahr, M A; Abe, N Soils Found II32, N1, March 1992, P161-172
A new procedure to determine design shear strength and consolidation yield stress is proposed. The methods currently in use are first reviewed and the difference in quality of field data returned in various parts of the world is demonstrated. The use of cone penetration, sheathed field vane, and direct shear tests to minimise this variation is suggested. Results are presented from tests in three marine clays. A correction factor to be applied to the results to obtain design parameters is described. It is shown that undisturbed samples are not necessary provided that vane shear and direct shear test results in the normally consolidated state are available.
Stress-strain-pore pressure relations of remoulded and undisturbed clays in static undrained shear were studied before and after cyclic loading. Attention is paid to the equivalent overconsolidation phenomenon observed for the normally consolidated samples in their subsequent response to undrained shear, and the equivalent overconsolidation hypothesis is proposed. Based on these results, shear characteristics degradation relations are constructed for remoulded and undisturbed normally consolidated clays. A method of predicting post-cyclic stress strain behaviour is proposed.
931063 Effects of cyclic loading on undrained strength and compressibility of clay Yasuhara, K; Hirao, K; Hyde, A F L Soils Found 1/32, N1, March 1992, P100-116 The effects of undrained cyclic loading on behaviour of clays have been studied, considering behaviour both during cycling and after cyclic loading. Triaxial tests were carried out on highly plastic reconstituted Ariake clay. The stress reversal occurring during undrained cycling accelerated generation of excess pore pressures and residual strains, leading to failure. Undrained strength decreases with the magnitude of induced excess pore pressure, whilst post cyclic undrained strength followed by drainage increases. Post cyclic recompression volume strains are governed by the magnitude of induced excess pore pressure. Methods for predicting both behaviours are presented.
931064 Pore pressure:stress ratio relationship for soft Bangkok clay Balasubramaniam, A S; Handali, S; Wood, D M Soils Found V32, N1, March 1992, Pl17-131 The development of pore pressure under monotonic loading conditions was examined in triaxial tests on undisturbed samples of Bangkok clay consolidated under different constant stress ratios. A linear relation is seen between pore pressure reached and stress ratio for isotropically consolidated samples in the normally consolidated state. Similar results are found in the literature for kaolin, Drammen, and Boston Blue clays. Overconsolidated and anisotropically consolidated samples showed bilinear variation on the same plot. Simple expressions are developed for the undrained stress paths for different initial conditions of the samples.
931065 Normalized undrained strength of clay in the normally consolidated state and in the field Hanzawa, H; Tanaka, H Soils Found V32, NI, March 1992, P132-148 Undrained strengths in the normally consolidated state, norrealized with respect to vertical consolidation stress, were obtained from Ko consolidated triaxial compression and extension tests and direct shear tests on clays with a range of plasticity index (Ip) from 5-100. Data are also presented for 7 clays from the Arabian Gulf, shear strengths from field vane, oedometer, and direct shear teStS, normalised with respect to effective overburden ratio and consolidation yield stress. The
931067 Point Ioad-Uniaxial compressive strength correlation Tsidzi, K E N Proc 7th I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V1, P637-639. Publ Rotterdam: A A Balkema, 1991 Uniaxial compressive strength of rocks is often inferred from point load test results, although no specific correlation factor (k) exists for all rock types, as this factor is sensitive to both external conditions of the specimens and intrinsic strength properties of the rocks. The extent to which k is influenced by the anisotropic fabric of the rock is critically examined using a suite of metamorphic rocks. The degree of foliation should be evaluated before assigning an appropriate k value for a particular metamorphic rock.
931068 Strength and deformation properties of saturated sands under static and cyclic loading Zaretsky, Y K; Vorontsov, E I; Baizakov, A A Proc lOth European Conference on Soil Mechanics and Foundation Engineering, Florence, 26-30 May 1991 V1, P175176. Publ Rotterdam: A A Balkema, 1991 Experimental results are presented on strength and deformation properties of saturated sands under true triaxial, plane strain, and conventional triaxial conditions subject to static and cyclic loading in consolidated drained and consolidated undrained tests. Samples of three initial densities were tested. Development of pore pressures and strains finally culminating in failure by liquefaction is discussed.
931069 Development of pore pressure and material damping during cyclic loading Jacobsen, H M; Ibsen, L B Proc lOth European Conference on Soil Mechanics and Foundation Engineering, Florence, 26-30 May 1991 V1, P219222. Publ Rotterdam: A A Balkema, 1991 A procedure to describe the behaviour of sand under cyclic loading is presented. In it, the deviator stress is normalised by introducing the mobilisation index, M (deviator stress/actual mean normal stress). This allows description of the strongly hysteretic behaviour during loading and unloading even under complicated stress paths. The development of stabilisation, instant stabilisation, pore pressure buildup, and liquefaction is illustrated and hysteretic curves and damping ratios calculated. The damping ratios agree well with those observed during cyclic triaxial tests on a uniform sand.
© 1993 Pergamon Press Ltd. Reproduction not permitted
correlation between normalised undrained strength and Ip reported by other workers is not seen. The effect of strain rate on undrained strength is independent of Ip.
931062 New approach to determine soil parameters free from regional variations in soil behaviour and technical quality Hanzawa, H Soils Found V32, N1, March 1992, P71-84
931066 Estimation of shear characteristics degradation and stressstrain relationship of saturated clays after cyclic loading Matsui, T; Bahr, M A; Abe, N Soils Found II32, N1, March 1992, P161-172
A new procedure to determine design shear strength and consolidation yield stress is proposed. The methods currently in use are first reviewed and the difference in quality of field data returned in various parts of the world is demonstrated. The use of cone penetration, sheathed field vane, and direct shear tests to minimise this variation is suggested. Results are presented from tests in three marine clays. A correction factor to be applied to the results to obtain design parameters is described. It is shown that undisturbed samples are not necessary provided that vane shear and direct shear test results in the normally consolidated state are available.
Stress-strain-pore pressure relations of remoulded and undisturbed clays in static undrained shear were studied before and after cyclic loading. Attention is paid to the equivalent overconsolidation phenomenon observed for the normally consolidated samples in their subsequent response to undrained shear, and the equivalent overconsolidation hypothesis is proposed. Based on these results, shear characteristics degradation relations are constructed for remoulded and undisturbed normally consolidated clays. A method of predicting post-cyclic stress strain behaviour is proposed.
931063 Effects of cyclic loading on undrained strength and compressibility of clay Yasuhara, K; Hirao, K; Hyde, A F L Soils Found 1/32, N1, March 1992, P100-116 The effects of undrained cyclic loading on behaviour of clays have been studied, considering behaviour both during cycling and after cyclic loading. Triaxial tests were carried out on highly plastic reconstituted Ariake clay. The stress reversal occurring during undrained cycling accelerated generation of excess pore pressures and residual strains, leading to failure. Undrained strength decreases with the magnitude of induced excess pore pressure, whilst post cyclic undrained strength followed by drainage increases. Post cyclic recompression volume strains are governed by the magnitude of induced excess pore pressure. Methods for predicting both behaviours are presented.
931064 Pore pressure:stress ratio relationship for soft Bangkok clay Balasubramaniam, A S; Handali, S; Wood, D M Soils Found V32, N1, March 1992, Pl17-131 The development of pore pressure under monotonic loading conditions was examined in triaxial tests on undisturbed samples of Bangkok clay consolidated under different constant stress ratios. A linear relation is seen between pore pressure reached and stress ratio for isotropically consolidated samples in the normally consolidated state. Similar results are found in the literature for kaolin, Drammen, and Boston Blue clays. Overconsolidated and anisotropically consolidated samples showed bilinear variation on the same plot. Simple expressions are developed for the undrained stress paths for different initial conditions of the samples.
931065 Normalized undrained strength of clay in the normally consolidated state and in the field Hanzawa, H; Tanaka, H Soils Found V32, NI, March 1992, P132-148 Undrained strengths in the normally consolidated state, norrealized with respect to vertical consolidation stress, were obtained from Ko consolidated triaxial compression and extension tests and direct shear tests on clays with a range of plasticity index (Ip) from 5-100. Data are also presented for 7 clays from the Arabian Gulf, shear strengths from field vane, oedometer, and direct shear teStS, normalised with respect to effective overburden ratio and consolidation yield stress. The
931067 Point Ioad-Uniaxial compressive strength correlation Tsidzi, K E N Proc 7th I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 V1, P637-639. Publ Rotterdam: A A Balkema, 1991 Uniaxial compressive strength of rocks is often inferred from point load test results, although no specific correlation factor (k) exists for all rock types, as this factor is sensitive to both external conditions of the specimens and intrinsic strength properties of the rocks. The extent to which k is influenced by the anisotropic fabric of the rock is critically examined using a suite of metamorphic rocks. The degree of foliation should be evaluated before assigning an appropriate k value for a particular metamorphic rock.
931068 Strength and deformation properties of saturated sands under static and cyclic loading Zaretsky, Y K; Vorontsov, E I; Baizakov, A A Proc lOth European Conference on Soil Mechanics and Foundation Engineering, Florence, 26-30 May 1991 V1, P175176. Publ Rotterdam: A A Balkema, 1991 Experimental results are presented on strength and deformation properties of saturated sands under true triaxial, plane strain, and conventional triaxial conditions subject to static and cyclic loading in consolidated drained and consolidated undrained tests. Samples of three initial densities were tested. Development of pore pressures and strains finally culminating in failure by liquefaction is discussed.
931069 Development of pore pressure and material damping during cyclic loading Jacobsen, H M; Ibsen, L B Proc lOth European Conference on Soil Mechanics and Foundation Engineering, Florence, 26-30 May 1991 V1, P219222. Publ Rotterdam: A A Balkema, 1991 A procedure to describe the behaviour of sand under cyclic loading is presented. In it, the deviator stress is normalised by introducing the mobilisation index, M (deviator stress/actual mean normal stress). This allows description of the strongly hysteretic behaviour during loading and unloading even under complicated stress paths. The development of stabilisation, instant stabilisation, pore pressure buildup, and liquefaction is illustrated and hysteretic curves and damping ratios calculated. The damping ratios agree well with those observed during cyclic triaxial tests on a uniform sand.
© 1993 Pergamon Press Ltd. Reproduction not permitted